Clean elemental copper powder can be formed, as by pressing, into a coherent "green" shape. Such shape then can be sintered and the sintered shape repressed to yield a substantially fully dense copper shape. Copper metal powder that has an oxidized surface is deoxidized prior to such a sequence.
Another conventional powder metallurgical process for making a copper metal shape comprises oxidizing small elemental copper pieces such as shot with air at elevated temperature to form preponderantly cuprous oxide, reducing the ground oxide to elemental copper, pressing the ground reduced copper into a cohesive mass, sintering that mass, and repressing the resulting sintered mass into final shape and density.
In the above-described operations the conventional sintering of a "green" copper powder shape or part often tends to isolate internal porosity, probably by closing off small channels in the "green" part undergoing sintering, thereby restricting ready attainment of high density in the sintered mass. Advantages of the instant invention over conventional powder metallurgy operations like those described above include opportunities for realizing greater economy, for avoiding contamination, and, most surprisingly, for enhancing the sintering.